Project description:Cytogenetic analysis of acute myeloid leukemia (AML) cells has accelerated the identification of genes important for AML pathogenesis. To complement cytogenetic studies and to identify genes altered in AML genomes, we performed genome-wide copy number analysis with paired normal and tumor DNA obtained from 86 adult patients with de novo AML using 1.85 million feature SNP arrays. Acquired copy number alterations (CNAs) were confirmed using an ultra-dense array comparative genomic hybridization platform. A total of 201 somatic CNAs were found in the 86 AML genomes (mean, 2.34 CNAs per genome), with French-American-British system M6 and M7 genomes containing the most changes (10-29 CNAs per genome). Twenty-four percent of AML patients with normal cytogenetics had CNA, whereas 40% of patients with an abnormal karyotype had additional CNA detected by SNP array, and several CNA regions were recurrent. The mRNA expression levels of 57 genes were significantly altered in 27 of 50 recurrent CNA regions <5 megabases in size. A total of 8 uniparental disomy (UPD) segments were identified in the 86 genomes; 6 of 8 UPD calls occurred in samples with a normal karyotype. Collectively, 34 of 86 AML genomes (40%) contained alterations not found with cytogenetics, and 98% of these regions contained genes. Of 86 genomes, 43 (50%) had no CNA or UPD at this level of resolution. In this study of 86 adult AML genomes, the use of an unbiased high-resolution genomic screen identified many genes not previously implicated in AML that may be relevant for pathogenesis, along with many known oncogenes and tumor suppressor genes.
Project description:<p>We performed genome-wide copy number analysis with paired normal and tumor DNA obtained from 86 adult patients with de novo AML using the Affymetrix Genome-Wide Human SNP array 6.0 containing 1.85 million features. Acquired copy number alterations (CNA) were confirmed using an independent, higher resolution, custom array comparative genomic hybridization platform.</p> <p>A total of 201 somatic CNA were found in the 86 AML genomes (mean 2.34 CNA/genome), with FAB M6 and M7 AML genomes containing the most changes (10-29 CNA/genome). Twenty-four percent of AML patients with normal cytogenetics had CNA, while 40% of patients with an abnormal karyotype had additional CNA detected by SNP array, and several regions contained CNA in multiple AML genomes. The mRNA expression levels of 57 genes were significantly altered in 27 of 50 recurrent CNA regions <5 megabases in size. Array data are available online at <a href="http://www.ncbi.nlm.nih.gov/geo/" target="_blank">http://www.ncbi.nlm.nih.gov/geo/</a> as GEO accession #GSE10358. A total of 8 uniparental disomy (UPD) segments were identified in the 86 genomes and 6/8 UPD regions occurred in samples with a normal karyotype. Collectively, 40% of AML genomes contained alterations not found with cytogenetics, and 96% of these regions contained known or novel AML associated genes. 43/86 AML genomes had no CNA or UPD at this level of resolution. The number of CNA per genome was not associated with overall survival, independent of cytogenetic classification.</p> <p>In this study of 86 adult AML genomes, subcytogenetic CNAs or UPD did not add prognostic information to standard cytogenetics. However, arrays identified many somatically mutated oncogenes and tumor suppressor genes, and also genes not previously implicated in AML that may be relevant for pathogenesis.</p> <p>AML CNA segments from 86 adult AML patients are available through dbVar at <a href="ftp://ftp.ncbi.nlm.nih.gov/pub/dbVar/data/Homo_sapiens/nstd11_Walter_et_al_2009">ftp://ftp.ncbi.nlm.nih.gov/pub/dbVar/data/Homo_sapiens/nstd11_Walter_et_al_2009</a>.</p>
Project description:Identification of Acquired Copy Number Alterations and Uniparental Disomies in Cytogenetically Normal Acute Myeloid Leukemia Using High-Resolution Single Nucleotide Polymorphism Analysis Recent advances in genome-wide single nucleotide polymorphism (SNP) analyses have revealed previously unrecognized microdeletions and uniparental disomy (UPD) in a broad spectrum of human cancers. As acute myeloid leukemia (AML) represents a genetically heterogeneous disease, this technology might prove helpful especially for cytogenetically normal AML (CN-AML) cases. Thus, we performed high-resolution SNP analyses in 157 adult cases of CN-AML. Regions of acquired UPD were identified in 12% of cases and most frequently affected chromosomes 6p, 11p, and 13q. Notably, acquired UPD was invariably associated with mutations in NPM1 or CEBPA that impair hematopoietic differentiation (P=0.008), suggesting that UPDs may preferentially target genes that are essential for proliferation and survival of hematopoietic progenitors. Acquired copy number alterations (CNAs) were detected in 49% of cases with losses found in two or more cases affecting e.g. chromosome bands 3p13-p14.1 and 12p13. Furthermore, we identified two cases with a cryptic t(6;11) as well as several non-recurrent aberrations pointing to leukemia relevant regions. With regard to clinical outcome, there appeared to be an association between UPD 11p and UPD 13q cases with overall survival. These data demonstrate the potential of high-resolution SNP analysis for identifying genomic regions of potential pathogenic and clinical relevance in AML.
Project description:<p>We performed genome-wide copy number analysis with paired normal and tumor DNA obtained from 86 adult patients with de novo
AML using the Affymetrix Genome-Wide Human SNP array 6.0 containing 1.85 million features. Acquired copy number alterations (CNA)
were confirmed using an independent, higher resolution, custom array comparative genomic hybridization platform.</p>
<p>A total of 201 somatic CNA were found in the 86 AML genomes (mean 2.34 CNA/genome), with FAB M6 and M7 AML genomes containing the
most changes (10-29 CNA/genome). Twenty-four percent of AML patients with normal cytogenetics had CNA, while 40% of patients with
an abnormal karyotype had additional CNA detected by SNP array, and several regions contained CNA in multiple AML genomes.
The mRNA expression levels of 57 genes were significantly altered in 27 of 50 recurrent CNA regions <5 megabases in size.
Array data are available online at <a href="http://www.ncbi.nlm.nih.gov/geo/" target="_blank">http://www.ncbi.nlm.nih.gov/geo/</a>
as GEO accession #GSE10358. A total of 8 uniparental disomy (UPD) segments were identified in the 86 genomes and 6/8 UPD regions
occurred in samples with a normal karyotype. Collectively, 40% of AML genomes contained alterations not found with cytogenetics,
and 96% of these regions contained known or novel AML associated genes. 43/86 AML genomes had no CNA or UPD at this level of resolution.
The number of CNA per genome was not associated with overall survival, independent of cytogenetic classification.</p>
<p>In this study of 86 adult AML genomes, subcytogenetic CNAs or UPD did not add prognostic information to standard cytogenetics.
However, arrays identified many somatically mutated oncogenes and tumor suppressor genes, and also genes not previously implicated
in AML that may be relevant for pathogenesis.</p>
<p>AML CNA segments from 86 adult AML patients are available through dbVar at
<a href="ftp://ftp.ncbi.nlm.nih.gov/pub/dbVar/data/Homo_sapiens/nstd11_Walter_et_al_2009">ftp://ftp.ncbi.nlm.nih.gov/pub/dbVar/data/Homo_sapiens/nstd11_Walter_et_al_2009</a>.</p>
Project description:In order to benchmark the reproducibility of Affymetrix Genome-Wide Human SNP Array 6.0 for detecting copy-number alterations, we performed replicate hybridizations of 3 tumor cell lines and 2 paired normal cell lines obtained from the American Type Culture Collection (ATCC). We calculated copy numbers at each SNP probeset by a custom copy-number pipeline (PMID: 18772890). For each cell line, copy number data from replicate arrays are supplied in the accompanying matrix files. For each SNP probeset, we calculated the median copy number across replicate arrays. We compared the copy-number alterations detected by Circular Binary Segmentation segmentation of these arrays with statistical analyses of short sequence reads obtained from the Illumina/Solexa 1G GenomeAnalyzer. Shotgun sequencing results can be found in the NCBI Short Read Archive, accession number SRP000246 Keywords: disease state analysis
Project description:This SuperSeries is composed of the following subset Series: GSE12019: Fine-scale mapping of copy-number alterations with massively parallel sequencing GSE13372: High-resolution mapping of copy-number alterations with massively parallel sequencing Refer to individual Series
Project description:In order to benchmark the reproducibility of Affymetrix 238K Sty arrays for detecting copy-number alterations. We performed replicate hybridizations of 3 tumor cell lines and 2 paired normal cell lines obtained from the American Type Culture Collection (ATCC). We calculated copy numbers at each SNP probeset by array pre-processing with the GISTIC algorithm (PMID: 18077431). For each SNP probeset, we calculated the median copy number across replicate arrays. The median copy number profile for each tumor cell line was segmented with the GLAD algorithm (PMID: 15381628) to partition the genome into regions of constant copy number. We compared the copy-number alterations detected by GLAD segmentation of these arrays with statistical analyses of short sequence reads obtained from the Illumina/Solexa 1G GenomeAnalyzer. Shotgun sequencing results can be found in the NCBI Short Read Archive, accession number SRP000246. Keywords: disease state analysis